352 Account of a new Method of Bleaching Cotton. 
upon by fecuring the feet with wooden thoes, When the alka- 
line liquor has well penetrated the cotton in an equal manner, 
it is to be carried to the boiler, and placed on the wooden 
grate already mentioned. The fuperfluous liquor will run 
down between the bars, and form a liquid firatum, which 
will permit the mafs to be heated without any danger of 
burning the cotton or the bottom of the boiler. To form 
the alkaline ley, foda of Alicant may be employed equal to a 
tenth part of the weight of the cotton on which you operate; 
and in a boiler fuch as I have defcribed, about 800 pounds 
of cotton may be fubjeéted to the procefs at one time. At 
the moment when the cotton is introduced and arranged in 
the boiler, the aperture at top is fhut, by its ufual covering, 
as clofely as poffible, in order that the vapours may affume 
a greater degree of heat, and re-aé& with more force on the 
cotton. The fire of the furnace is then to be kindled *, and 
the ley muft be kept in a ftate of flight ebullition for from 
twenty to thirty-fix hours. It is then fuffered to cool, and 
the cotton being carefully wafhed, muft be expofed on the 
grafs for two or three days, extending’ it on poles in the day- 
time, and fpreading it out on the grafs during the night. The 
cotton will then have acquired a fuperb degree of whitenefs ; 
and if, by chance, any parts of the cotton are ftill coloured, 
it muft be put into the kettle a fecond time, or be expofed a 
few days longer on the grafs. Thefe fhades in the bleached 
cotton are owing in particular to its not having been all 
equally and completely impregnated with the ley; they may 
arife alfo from the arrangement of the cotton in the boiler, if. 
it has been heaped up too much in certain points. When it 
is judged that the ley has been exhaufted by ebullition, the 
cover of the kettle is to be taken off, and the dry cotton mut. 
be befprinkled with a new folution of foda; without this pre- 
caution it might run the danger of Baile burnt, It might 
readily be judged, by eftimating the fub tances and time 
employed in this operation, that it is attended with econo- 
mical advantages; but we have a more fimple method of af- 
* In giving the above dimenfions, I have fuppofed the fuel ufed to be 
coal : if wood is burnt, the dimenfions muft be varied. In the latter cafe 
the bottom of the kettle would be too high above the bottom of the furnace. 
certaining 
SS 
